The Dutch Republic — officially known as the Republic of the Seven United Netherlands (Republiek der Zeven Verenigde Nederlanden), the Republic of the United Netherlands, or the Republic of the Seven United Provinces (Republiek der Zeven Verenigde Provinciën) — was a republic in Europe existing from 1581 to 1795, preceding the Batavian Republic, the United Kingdom of the Netherlands and ultimately the modern Kingdom of the Netherlands. Alternative names include the United Provinces, Foederatae Belgii Provinciae (Federated Belgic Provinces), and Belgica Foederata (Belgic Federation).

Until the 16th century, the Low Countries – roughly now corresponding to Netherlands, Belgium and Luxembourg – consisted of a number of duchies, counties and bishoprics, most of which were under the supremacy of the Holy Roman Empire.

Most of the Low Countries had come under the rule of the House of Burgundy and subsequently the House of Habsburg. In 1549 Holy Roman Emperor Charles V issued the Pragmatic Sanction, which further unified the Seventeen Provinces under his rule. Charles was succeeded by his son, King Philip II of Spain. In 1568 the Netherlands, led by William I of Orange, revolted against Philip II because of high taxes, persecution of Protestants by the government, and Philip's efforts to modernize and centralize the devolved-medieval government structures of the provinces. This was the start of the Eighty Years' War.

Carl Edward Sagan ( /ˈseɪɡɪn/; November 9, 1934 – December 20, 1996) was an American astronomer, astrophysicist, cosmologist, author, science popularizer, and science communicator in astronomy and natural sciences. He published more than 600 scientific papers and articles and was author, co-author or editor of more than 20 books. He advocated scientifically skeptical inquiry and the scientific method, pioneered exobiology and promoted the Search for Extra-Terrestrial Intelligence (SETI).

Sagan is known for his popular science books and for the award-winning 1980 television series Cosmos: A Personal Voyage, which he narrated and co-wrote. The book Cosmos was published to accompany the series. Sagan wrote the novel Contact, the basis for a 1997 film of the same name.

Carl Sagan was born in Brooklyn, New York, to a Ukrainian Jewish family. His father, Sam Sagan, was an immigrant garment worker from Kamenets-Podolsk, Ukraine; his mother, Rachel Molly Gruber, a housewife. Carl was named in honor of Rachel's biological mother, Chaiya Clara, in Sagan's words, "the mother she never knew." Sagan graduated from Rahway High School in Rahway, New Jersey, in 1951.